Athena can't believe it's almost her little sister Hebe's birthday...or that it's been a year since Athena found herself at Mount Olympus Academy. It turns out Athena and her BFFs, the Goddess Girls, remember very different versions of Athena's first day at school. To see what really happened, they use a spell to travel back in time!

The girls go back a year earlier but to ancient Rome instead of Greece--where they meet the Roman equivalents of themselves! With time running out for them to get back to Greece--and for Hebe's celebration!--can the Goddess Girls work with their new friends to find their way home?